1. Field of the Invention
The present invention relates to an apparatus for guarding a pressure sensor for a washing machine, which adjusts the water level of washing water being supplied into the washing machine, and more particularly to an apparatus for guarding a pressure sensor for a washing machine, which can block an inflow path of washing water when the pressure sensor malfunctions.
2. Background of the Related Art
In general, a washing machine is an appliance that washes laundries through washing, rinsing, and dehydrating processes by the action of water being supplied into a washing tank and a detergent, and is provided with a pressure sensor that properly adjusts the water supply amount in accordance with a water level preset by a controller or a water level directly set by a user.
The pressure sensor is to adjust the water level of washing water in accordance with the change of an oscillation frequency of an LC oscillation circuit. Since a controller judges whether to operate a water supply device and a drain device and successively outputs on/off signals thereto, the washing water supply amount can be optimized to reduce unnecessary waste of water.
For example, according to a pressure sensor previously filed by the applicant (Korean Patent Publication No. 1995-7460), as shown in FIG. 1, a diaphragm 140 is built in a space part 120 of a housing 110 to operate in accordance with the water pressure of washing water being supplied to an inlet C, a metal core 150 is mounted on an upper surface of the diaphragm 140 to be in close elastic contact with the upper surface of the diaphragm 140 through a coil spring 130, and a first sensing part 160 is installed in a moving path of the metal core 150 to output a signal required for adjustment of a water level of the washing water.
In this case, the first sensing part 160 has a structure that adjusts the washing water supply amount in accordance with a reactance value of a bobbin on which a coil is wound.
Accordingly, when the washing water is supplied to the inlet C of a pressure sensor 100, the metal core 150 mounted on the diaphragm 140 ascends/descends according to the water pressure, and thus the washing water supply amount is adjusted as much as the amount of ascent/descent of the metal core 150 in accordance with an output signal of the first sensing part 160.
However, the pressure sensor 100, which has a structure that adjusts the washing water supply amount in accordance with an output signal of the first sensing part 160, is not provided with a safety device that compensates for malfunction of the first sensing part 160 when such malfunction is generated, and thus it may lose the function of adjusting the water level of washing water, which is the inherent function of the pressure sensor.
In addition, if the washing water more than a prescribed amount is supplied due to the malfunction of the pressure sensor 100, the on/off time of the washing machine may be lengthened or shortened, and further laundries may get tangled or become decolorized or discolored to cause the damage of the laundries themselves.
Accordingly, if the washing water more than or less than the prescribed amount is supplied through the inlet C due to the malfunction of the pressure sensor 100, the water level adjustment function of the pressure sensor is lost, and thus the washing work cannot be smoothly performed. In this case, due to the overflow of the washing water, surrounding environment may be polluted.